1、CSS3
/* Small devices (portrait tablets and large phones, 600px and up) */
@media only screen and (min-width: 600px) {
.example {background: green;}
}
/* Medium devices (landscape tablets, 768px and up) */
@media only screen and (min-width: 768px) {
.example {background: blue;}
}
/* Large devices (laptops/desktops, 992px and up) */
@media only screen and (min-width: 992px) {
.example {background: orange;}
}
/* Extra large devices (large laptops and desktops, 1200px and up) */
@media only screen and (min-width: 1200px) {
.example {background: pink;}
}
http://www.runoob.com/cssref/css3-pr-mediaquery.html
2.Bootstrap.v3
3.Bootstrap.v4
https://v4.bootcss.com/docs/4.0/layout/overview/